Solve for $z$ : $-19 = -26 + z$
Add $26$ to both sides: $ \begin{eqnarray} \\ \hphantom{-19 {+ 26}} &\hphantom{=}& \hphantom{z} \\ -19 &=& -26 + z \\ \\ {+26} && {+26} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ -19 {+ 26} &=& z \\ \end{eqnarray} $ Simplify. $ z = 7$